Air pump



A. BURN'AM.

AIR PUMP. 'APPLlcATloN met) 11011.19, 1920.

Patented May 2,1922,

2 sHEEs-SH'EET 1.

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A .Barna/zw A. BURNAM.

AIR PUMP.

M PLICATION FILED NOV. 19. i920.v

Patented May 2, 1922.

2 SHEETS-SHEET 2.

www0-ovv" ,ooo 9,000,000.00.

UNITED 'STATES PATENT omer..

ALLEN BURNAM, or SAN ANTONIO, TEXAS, AssIGNon or ONE-HALF 'ro o. M.- HOCKER,

or SAN ANTONIO, TEXAS, l

A1B. PUMP.y

provide apump. employing kavsi'ngle cylinder and ai' single discharge" pipe and wherein an improved valve mechanism will be employed for f alternately cutting off communication between one end of thecylinder andthe adjacent end of the pipeand'coincidently establishing communication between the other end ofthe cylinder and the other end ofthe pipe.

And the invention has as a still turtherobject to provide a pump employing opposed discharge valves forcontrolling communication y between the cylinder and discharge pipe, wherein said Vvalves-will be normally Vheld closed by a spring common to both thereof, and wherein movement of either valve to open position will serve to increase the tension ot the springagainst the other valve for binding the latter valve closed.

Other and incidental objects will appear hereinafter.

In the drawings:

Figure 1 is a side elevation of my improved pump.

Figure 2 is a vertical sectional view showing the piston on the down stroke,

Figure 3 is a vertical sectional view showingjhe piston on the up stroke,

igure l is a transverse section on the line 4--4 of Figure 3, looking in the direction of the arrows, and

Figure 5 is a detail elevation showing one of the discharge valves employed.

In carrying the invention into effect, l employ a pump base 10 -into which is threaded a cylinder 11. At one side ot-the cylinder, the base is formed with a valve chamber 12 at the lower end ot which is a sea-t 13 and establishing communication between the valve chamber and the cylinder is a passage 14. -Surrounding theV valve chamber is an upstanding nipple 15.

Specification of Letters Patent. 'Patented NIay 2, 1922,

'.Appncation filed November 19, i920. serial No. 425,179. i

Threaded upon the upper end ot' the cylinder is a head or cap 1G provided axially with a depending sleeve. 17 and slidable through said sleeve is a hollow piston rod 18, a gland 19 being threaded into the head to surround said rod. Removably Vmounted upon the lower end portion of the rod is a piston 20, the leathers of which 'are formed to coact with the wall ot the cylinder and threaded lupon the lower end or the rod below v'said lpiston 1sv a'l tubular valvecage 21 which cary ries, vnear its lower end, 'a cross pin 22. Freely movable` within the cage to seat against the lower end of the rod is a lvalve 23 movable tojopen position sustained by the cross pin. Formed through the head 16`is an 'air inlet passage 24- andfslidably surroundingv the sleeve '17 is a valve 25 movableto overlie ,said passage, the valve-being normally held closed by' a spring 26 surrounding thesleeve.

As willpbe observed,` this'spring, as well as the' valve, is removably held in position by a nut 27 threaded upon the lower end of the sleeve. The valve preferably comp-rises a metallic ringand overlying said ring isla.

fiber or other approved unisher forsea-ling the passage 24, the ring and washer loosely fitting the sleeve 17. Remo-vably fitted upon the upper end portion of the piston rod is a handle 28 below which is a suitable stop nut while 'above the handle is arranged a( hollow stop cap 28 which is threaded upon the rod and provided with suitable perforations in the side wall thereof,.the cap serving, of course, to removably hold the handle in position. Depending from the head 16 at one side of the cylinder 11 is a nipple 29 alining with the nipple 150i the base 1() and surrounding a valve chamber 30 within the head. At the lower end of this chamber is a seat 31 and leading through the head from said chamber is a passage 32 establishing communication between the chamber and the cylinder. Fitting at its ends in the nipples 15 and 29 is a discharge pipe 33 at the end portions of which are glands 34 threaded upon said nipples, and threaded into the pipe at a point substantially midway between the ends thereof is a discharge nipple 35 to which is detachably connected a discharge hose 36. This hose may be equipped at its free end with any approved connection for engagement with the casing of a tire valve. Loosely fitting in the discharge pipe 33 is a helical spring 37 extending from end to end of the as will be observed, the convolutions of the spring 37 at the end portions oi'said spring,

engage in said `grooves, the spring surrounding and gripping the valves 'for securely holdingthe valves thereon. Thus, as will be seen the spring will normally hold the valve 38 closed in engagement with the seat 3l and also coincidently hold the valve 39 closed in engagement with the seat 13. y

issuming now that the pump piston is,

as shown in Figure 2, moving downwardly,

it will `be seen that the valve .25 will move to open,v osition sot-hat air will bel admitted heliinc the piston 4through the inlet passage 24 While the valve 23l will close against its seat.v l Accordingly, air inthe cylinder'below* the piston will be forced through the passage 14 into the valve chamber l2 so that the valve .39 will ybe opened. Opening movement of thisvalve ywill serve to vincrease the :upward L tensionv ofthe spring 37v for binding the valve 38 closed sok that the air will be discharged throughjtheV nipple 35and hose 36. Upon upward movement of the piston, as shown in Figuref3, the valve y23 will move to. open position 'fior 'admitting air below the piston Vectively prevented.

ingin said grooves, the @spring normally 70 through the piston rod 18 while the valve 25 will close. Air within the cylinder above the piston will accordingly .be forced through the passage 32 and through the valve chamber 30 for opening the valve 38. Opening movement Vof this valve will serve to increase 'the downward tension of the spring 37v for binding the valve 39 closed. Accordingly, like when the piston is moving downwardly, air will be dischaiged'through the nipple 35 and hose 36. It will thus be seen that the pump is double acting. Further, it 'will be note-d that while the spring 37 will normally hold both of the valves 38 and 39 closed, the structure is such that the opening movement ofeitheivalve will serve to increase the te f sion of the springagainst the other valve for binding the latter valve closed. Leakage past the discharge valves will x 'ccordingly'be ef- Having" thus.V des'erbed., v,the whatj'isclaimed as' newr is: 'l i l l An airpump includinga cylinder, Va pistonl reciprocable therein, means controlling. ad-

mission of air at opposite sides of lthe piston, a discharge pipe incommuiiication withopposite end portions of the cylinder,'di'scharge valves associated with said pipe controlling provided with'peripherahgrooves, and aV spring extending between said valves andxat its end portions encircling the valves engagholding the'valves closed.

` 'In testimony whereof myfsignature. Y Y' o ALLEN "BuiiNiiizi [1.. 5.,]-

mation 65v flow in opposite directions therethrough and Y 

